Effect Of Feed Rate Research Articles

Effect of feeding rats on gamma irradiated flour infected with Tribolium confusum

Effect of feeding rats on gamma irradiated flour infected with Tribolium confusum

Researching the Effects of Feedrate and Diamond Grain Size on Edge Chipping of Milled Granites

Researching the Effects of Feedrate and Diamond Grain Size on Edge Chipping of Milled Granites

Minor Constituents in Rice Bran Oil and Sesame Oil Play a Significant Role in Modulating Lipid Homeostasis and Inflammatory Markers in Rats.

The effects of feeding rats with groundnut oil (GNO), rice bran oil (RBO), and sesame oil (SESO) on serum lipids, liver lipids, and inflammatory markers were evaluated in rats. Male Wistar rats were fed with AIN-93 diet supplemented with 10 wt% of GNO, RBO, and SESO in the form of native (N) and minor constituent-removed (MCR) oils. Rats given RBO and SESO showed significant reduction in serum and liver lipids, 8-hydroxy-2-deoxyguanosine, cytokines in liver, and eicosanoids in leukocytes as compared with the rats given GNO and MCR oils. The rats fed with native oils of RBO and SESO showed an upregulation of sterol regulatory element-binding protein (SREBP)-2 and peroxisome proliferator-activated receptor gamma (PPARγ) and downregulation of nuclear factor-kappa B (NF-κB) p65. These effects of native oil were significantly compromised when rats were given MCR oils. In conclusion, the minor constituents significantly support the hypolipidemic and anti-inflammatory properties of RBO and SESO.

Diet containing partially hydrogenated vegetable fat enhances the carrageenan induced paw inflammation but not oxidative stress markers in liver of rats.

In the present study, we investigated the effect of feeding Partially hydrogenated vegetable fat (PHVF) on carrageenan induced paw inflammation and oxidative stress markers in liver of rats. In addition, the effect of feeding rats with Linseed Oil (LSO, α-linolenic acid, n-3 PUFA) or PHVF blended with incremental amounts of LSO on these markers were also monitored. Rats weighing 200g were given 1mL of different oils (PHVF, Groundnut Oil; GNO, Olive Oil; OO and LSO) per day for 15days. Rats given PHVF showed higher levels of paw inflammation in response to carrageenan injection. Rats given LSO showed least amounts of paw inflammation when injected with carrageenan. A second set of experiment was conducted by feeding weaning rats with AIN-93 purified diet supplemented with PHVF or PHVF with incremental amounts of LSO for 60days. The rats fed PHVF showed higher degree of carrageenan induced inflammation as compared to rats given GNO and LSO. However, the rats fed PHVF showed lower levels of lipid peroxides, protein carbonyls, 8-hydroxy guanine and antioxidant enzyme activities in liver homogenate as compared to those given LSO. In conclusion dietary PHVF rendered the rats prone to higher levels of carrageenan induced inflammation which can be reduced by giving PHVF blended with LSO. However, oxidative stress markers found to be higher levels in rats given LSO or PHVF blended with LSO as compared to rats given PHVF as sole source of fat.

Rats fed linseed oil in microemulsion forms enriches the cardiac sarcoplasmic reticulum lipids with docosahexaenoic acid and lower calcium transport

The effect of feeding rats with whey protein or lipoid microemulsion of n-3 rich linseed oil (LSO), and n-6 rich sunflower oil (SNO) compared to native or microemulsion forms of each oil for 60days on fatty acid composition, Ca2+Mg2+ ATPase, Ca2+ uptake and membrane fluidity of rat cardiac sarcoplasmic reticulum (SR) were assessed. Rats consuming LSO in lipoid microemulsion showed higher levels of ALA (18:3, n-3) conversion to DHA (22:6, n-3) when compared to rats given LSO in native form. Compared to all other dietary treatments, the alterations in the n-6/n-3 PUFA composition of SR of rats given LSO in lipoid microemulsion effected the greatest changes in Ca2+Mg2+ ATPase activity and Ca2+ uptake which effectively reduced Ca2+ transport. Therefore, the LSO in lipoid microemulsion confers similar heart healthy fatty acid compositional and calcium transport changes and potentially anti-arrhythmic effects similar to fish oils.

Influence of Extrusion Processing on Fatty acids Retention in Full-fat Flaxseed (Linum usitatissimum L.) Meal

Background: Flaxseed (Linum usitatissimum L.) provides multiple nutritional benefits including high quality protein, dietary fiber and is the most abundant source of α-linolenic acid (C 18:3). This study focuses on the effect of extrusion processing on fatty acids retention in full-fat flaxseed meal. The ranges of processing variables selected using central composite design were: barrel exit temperature (BET) of 76.3-143.6°C; screw speed (SS) of 59.6-160.5 rpm and feed rate (FR) of 26.4-93.6 kg/h. Results: The extrusion processing at different barrel temperatures, screw speed and feed rate did not showed gradual decrease or increase in palmitic, stearic, oleic and linoleic acid contents. The amount of α-linolenic acid retention in extruded samples ranged from 92% to 99.2%. Optimal operating conditions were established; BET (138.4-138.8°C), SS (160-160.5 rpm) and FR (26.4-34.1 kg/h) for maximum (98.3-98.8%) retention of α-linolenic acid. This effect was mainly dependent on BET (p≤0.01), whereas mutual interaction effect of BET, SS and FR was found to be non-significant ( p˃0.05). Conclusions: The results of this study demonstrated that the extrusion processing can be successfully explored to produce fatty meals with significant fatty acids retention for commercially food or feed purposes.

Relationship between Feedrate and Fatigue Life of Al7075-T6 Specimens before and after Shotpeening

This paper presents a study on the relationship between feedrate and fatigue life of Al7075-T6 specimens before and after shotpeening. For this purpose, six groups of specimens, each of which consists of eight specimens, were first machined at six different feedrates (0.05, 0.10, 0.15, 0.20, 0.25, 0.30 mm/rev). Half of eight specimens in each group were then peened and the others remained un-peened. Next, the fatigue life was measured by using 4-point rotary bending machine. One observation was that the fast the feedrate was, the large the mean diameter of a specimen was. To apply the same bending stresses in all cases, different loading conditions were thus recalculated and applied to specimens based on their mean diameters. Finally, the effect of feedrate on the fatigue life was estimated by comparing twelve sets of specimens (six groups times two sets, peened and un-peened).

Glucocorticoids and cyclic AMP selectively increase hepatic lipin-1 expression, and insulin acts antagonistically

Glucocorticoids (GCs) increase hepatic phosphatidate phosphatase (PAP1) activity. This is important in enhancing the liver's capacity for storing fatty acids as triacylglycerols (TAGs) that can be used subsequently for beta-oxidation or VLDL secretion. PAP1 catalyzes the conversion of phosphatidate to diacylglycerol, a key substrate for TAG and phospholipid biosynthesis. PAP1 enzymes in liver include lipin-1A and -1B (alternatively spliced isoforms) and two distinct gene products, lipin-2 and lipin-3. We determined the mechanisms by which the composite PAP1 activity is regulated using rat and mouse hepatocytes. Levels of lipin-1A and -1B mRNA were increased by dexamethasone (dex; a synthetic GC), and this resulted in increased lipin-1 synthesis, protein levels, and PAP1 activity. The stimulatory effect of dex on lipin-1 expression was enhanced by glucagon or cAMP and antagonized by insulin. Lipin-2 and lipin-3 mRNA were not increased by dex/cAMP, indicating that increased PAP1 activity is attributable specifically to enhanced lipin-1 expression. This work provides the first evidence for the differential regulation of lipin activities. Selective lipin-1 expression explains the GC and cAMP effects on increased hepatic PAP1 activity, which occurs in hepatic steatosis during starvation, diabetes, stress, and ethanol consumption.

Stability analysis for milling process

In this article, the stability of a milling process is studied by using a semi-discretization method. The model of the workpiece–tool system includes loss-of-contact effects between the workpiece and the tool and time-delay effects associated with the chip-thickness variation. In addition, feed-rate effects are also considered. The governing system of equations is a non-autonomous, delay-differential system with time-periodic coefficients. Stability of periodic orbits of this system is studied to predict the onset of chatter and numerical evidence is provided for period-doubling bifurcations and secondary Hopf bifurcations. Stability charts generated using the semi-discretization method are found to compare well with the corresponding results obtained through time-domain simulations.

Mechanisms involved in the chemoprevention of flavonoids.

Flavonoids, widespread in edible plants, have been studied extensively for their anticarcinogenic properties. However, only few studies have been done with these constituents being administered by the dietary route. In our research, the effects of feeding rats with flavone, flavanone, tangeretin, and quercetin were investigated on two steps of aflatoxin B1 (AFB1)-induced hepatocarcinogenesis (initiation and promotion). Nonpolar flavonoids such as flavone, flavanone and tangeretin administered through the initiation period, decreased the number of -gamma-glutamyl transpeptidase-preneoplastic foci. In the same conditions of administration, quercetin, a polyhydroxylated flavonoid, showed no protective effect. Moreover, feeding rats with flavanone during the phenobarbital-induced promotion step significantly reduced the areas of placental glutathione S-transferase preneoplastic foci. Quercetin, flavone, and tangeretin, administered in the same conditions, caused no significant effect. Therefore flavanone act as an anti-initiator as well as an anti-promotor. Several mechanisms were involved in the anti-initiating effects of flavone, flavanone, and tangeretin: enhancement of enzymes involved in the detoxication of AFB1 (glutathione S-transferase, UDP-glucuronyl transferase), increase of the formation of AFB1-glutathione conjugates and inhibition of the binding of AFB1 to DNA. Although the relevance of these data to the human situation remains to be demonstrated, they confirm that several flavonoids administered by the dietary route possess promising chemoprotective effects.

Dietary alpha-linolenic acid increases the biosynthesis of the choline glycerophospholipids from [14C]CDPcholine in rat liver and kidney but not in brain.

The effect of feeding rats for 30 days with diets containing high levels of linoleic acid (sunflower oil, SO) or alpha-linolenic acid (perilla oil, PO) was studied in the liver, kidney and brain. The PO group showed a higher labeling of choline glycerophospholipids (CGP) in liver and kidney but no difference with the SO group in ethanolamine glycerophospholipids (EGP) labeling. The brain displayed the lowest incorporation of both precursors and no difference between the two diets. Analyses of brain CGP and EGP fatty acid composition showed that in the PO group the ratio n-6/n-3 was lower than in the SO group, mainly as a consequence of lower levels of n-6 fatty acids. The mole % of docosahexaenoate (DHA) in these lipids was the same for both groups and only triacylglycerols (TAG) displayed a higher DHA. Therefore, at least in the brain, the magnitude of fatty acid changes observed in CGP and EGP for the PO group does not affect the uptake/incorporation of the precursors into phospholipids.

Effects of Feedrate and Chisel Edge on Delamination in Composites Drilling

Delamination accompanied with the drilling of composite laminates has been recognized as a major problem. An analytical model is established to predict critical thrust force and critical feedrate at which the delamination crack begins to propagate. For unidirectional composites, the delamination zone is modeled as an elliptical plate, with clamped edges and subjected to a central load. Based on fracture mechanics, laminated plate theory and cutting mechanics, expressions are developed for critical thrusts and critical feedrates at which delamination is initiated at different ply locations. This model has been verified by experiments. A variable feedrate strategy is formulated based on this model, which avoids delamination while drilling in a time-optimal fashion. In addition, the need to modify tool geometry to avoid delamination is highlighted. Chisel edge width has been identified as an important factor contributing to the thrust force and hence delamination.

Evaluation of the nutritive value of yellow rice in rats and broiler chicks.

Yellow discoloration often develops in rice kernels during post-harvest storage, due possibly to fungal activity. The present study examined the changes in nutrient composition taking place during yellowing of rice, and the effects of feeding rats and broiler chicks on a moderately yellow rice at 600 g/kg diet. Nitrogen content was found to be higher in rice grains that had become more yellow, only part of the increase being in non-protein-N; however, relative to crude protein (N x 6.25) the concentrations of lysine, methionine, cystine and arginine were lower. There were no significant differences between white and yellow rice in the food intake, weight gain and efficiency of food utilization (EFU) of rats and chicks when diets were formulated to contain similar nutrient concentrations, or the same basal ingredient composition. Diet pelleting increased food intake and weight gain in both animal species, but reduced dry matter and energy digestibility in rats; effects on nutrient retention in chicks were largely non-significant. Liver weights of rats and chicks and pancreas weights of chicks were unaffected by yellow rice; however, chicks fed on mash had a larger pancreas on average than those fed on pellets. Thus, whilst the nutrient composition of rice is altered during yellowing, a moderately yellow rice is unlikely to produce major adverse effects when fed to rats and broiler chicks.

Studies of dihydroxyacetone phosphate acyltransferase in rat small intestine. Subcellular localization and effect of partially hydrogenated fish oil and clofibrate.

The subcellular localization of dihydroxyacetone phosphate acyltransferase (DHAPAT) activity in rat small intestine was investigated by Nycodenz-gradient centrifugation. We found that DHAPAT had a predominant peroxisomal distribution, with a separate enzyme activity located in the microsomal fraction, the same distribution as found in rat liver. The effect of feeding rats on a diet with 20% (w/w) partially hydrogenated fish oil (PHFO) or 0.3% clofibrate on the activity of DHAPAT in rat small intestine and liver was studied. Both 20% PHFO and 0.3% clofibrate gave a 1.8-fold stimulation of the specific activities of DHAPAT in peroxisomes of the small intestine, whereas in the liver 20% PHFO gave a 1.4-fold stimulation and 0.3% clofibrate a 1.6-fold stimulation of the total DHAPAT activities in the postnuclear supernatant. The specific activities of DHAPAT in liver were not affected.

Effects of essential fatty acid deficiency on gamma-glutamyltranspeptidase activity of rat pancreas

The effect of feeding rats with an essential fatty acid-deficient or -sufficient diet for a total of 29 1 2 weeks ( 1 1 2 weeks of pregnancy, 4 weeks of lactation and 24 weeks postweaning) on gamma-glutamyltranspeptidase activity and fatty acid composition of pancreas were determined. Enzyme activity of essential fatty acid-deficient rats was significantly higher than in controls. Ina group of 24-week-old, essential fatty acid-deficient rats, the sufficient diet was fed for 8 weeks. Pancreatic gamma-glutamyltranspeptidase activity and fatty acid composition were restored to normal, suggesting a modulating effect of the diet. The results indicated that elevated gamma-glutamyltranspeptidase activity of essential fatty acid-deficient rat pancreas was reverted to normal by feeding an essential fatty acid-sufficient diet.

Effect of Fish Oil and Coconut Oil on Antioxidant Defence System and Lipid Peroxidation in Rat Liver

Diets high in fish oil containing polyunsaturated fatty acids of the n-3 family, have been suggested to decrease the risk of cardiovascular disease. However these lipids are highly susceptible to oxidative deterioration. In order to investigate the influence of n-3 fatty acids on oxidative status, the effect of feeding rats with fish oil or coconut oil diets was studied by measuring different parameters related to an oxidative free radical challenge. Synthetic diets containing 15% (w/v) fish oil or coconut oil were used to feed growing rats for 4 weeks. As compared to control diet, the fish oil containing diet produced a significant decrease of cholesterol and triglyceride concentration in serum, however there was a significant increase in lipid peroxidation products. In addition, in fish oil fed animals, there was also a decrease in vitamin E and A concentration. Furthermore, the rate of lipid peroxidation in isolated microsomes was three fold higher in rats fed fish oil as compared to rats with coconut oil diet. No significant differences between the two experimental groups were observed in superoxide dismutase (SOD) and phospholipid hydroperoxide glutathione peroxidase (PHGPX) activities. However, there was a decrease in glutathione peroxidase (GPX) activity. These results suggest that fish oil feeding at an amount compatible with human diet, although decreasing plasma lipids, actually challenge the antioxidant defence system, thus increasing the susceptibility of tissues to free radical oxidative damage.

The effect of feeding rats with partially hydrogenated marine oil or rapeseed oil on the chain shortening of erucic acid in perfused heart

1. 1. The metabolism of [14- 14C]erucic acid and [U- 14C]palmitic acid was studied in perfused hearts from rats fed diets containing hydrogenated marine oil, rapeseed oil or peanut oil for three weeks. 2. 2. [ 14C]Erucic acid was shortened to [ 14C]eicosenoic acid (20: 1, n — 9) and [ 14C]oleic acid (18 : 1, n — 9) in perfused rat hearts from all diet groups. The rapeseed oil diet caused a three-fold increase and the marine oil diet a fourfold increase in the amount of chain-shortened products recovered in heart lipids at the end of perfusion, compared to peanut oil diet. 3. 3. The content of C 16:1, C 18:1 and C 20:1 fatty acids was increased in heart lipids of rats fed hydrogenated marine oil or rapseed oil diet, compared to peanut oil diet. 4. 4. Feeding hydrogenated marine oil or rapeseed oil to the rats induced a 85% increase in catalase activity, a 20% increase in the activity of cytochrome oxidase and a 30–40% increase in the content of total CoA in the heart compared to rats fed peanut oil diet. 5. 5. It is suggested that [14- 14C]erucic acid is shortened by the β-oxidation system of peroxisomes in the heart. The increased chain shortening in the hearts from animals fed rapeseed oil or partially hydrogenated marine oil for three weeks may be an important part of an adaptation process.

The involvement of glucocorticoids in regulating the activity of phosphatidate phosphohydrolase and the synthesis of triacylglycerols in the liver. Effects of feeding rats with glucose, sorbitol, fructose, glycerol and ethanol

Feeding rats with sorbitol, fructose, glycerol and ethanol increases the concentration of serum corticosterone without significantly altering the concentration of insulin. This increase appears to be partly responsible for the increases in the hepatic activity of phosphatidate phosphohydrolase (compared with rats fed glucose or 0.9% NaCl) that has been reported [Sturton, Pritchard, Han & Brindley (1978) Biochem. J. 174, 667--670] and the enhanced capacity of the liver to synthesize triacylglycerols. The ethanol-induced increase in phosphohydrolase activity was largely, but not completely, prevented by adrenalectomy.

Role of vitamin a in chemical carcinogenesis of the mammary gland

The effect of feeding rats with high doses of vitamin A on the distribution of polycyclic hydrocarbon, 7,12-dimethylbenzanthracene (DMBA) and its metabolites in different organs and blood, and also on the metabolic rate in the liver was studied following intravenous injection of the carcinogen. Hypervitaminosis A resulted in a significant decrease of the level of DMBA and its metabolites in all the organs investigated and in the blood. The rate of DMBA metabolism in the liver of the animals rose with the increase of the vitamin A dose.

An examination of the effects of feeding rats upon tannia, a member of the family arace˦

An examination of the effects of feeding rats upon tannia, a member of the family arace˦